我參加了使用 laravel 的電子商務培訓，我想通過 paypal 購物車進行在線支付，但它在payment_gateway表格訂單領域給我錯誤，Column not found: 1054 Field 'payment_gateway' unknown in field list。你好，我參加了一個使用 laravel 的電子商務培訓，我想通過 paypal 購物車進行在線支付，但它在payment_gateway表格訂單領域給我錯誤，Column not found: 1054 Field 'payment_gateway' unknown in field list。checkoutController.php/**     * Store a newly created resource in storage.     *     * @param  \Illuminate\Http\Request  $request     * @return \Illuminate\Http\Response     */    public function paypalCheckout(Request $request)    {        // Check race condition when there are less items available to purchase        if ($this->productsAreNoLongerAvailable()) {            return back()->withErrors('Sorry! One of the items in your cart is no longer avialble.');        }        $gateway = new \Braintree\Gateway([            'environment' => config('services.braintree.environment'),            'merchantId' => config('services.braintree.merchantId'),            'publicKey' => config('services.braintree.publicKey'),            'privateKey' => config('services.braintree.privateKey')        ]);        $nonce = $request->payment_method_nonce;        $result = $gateway->transaction()->sale([            'amount' => round(getNumbers()->get('newTotal') / 100, 2),            'paymentMethodNonce' => $nonce,            'options' => [                'submitForSettlement' => true            ]        ]);        $transaction = $result->transaction;        if ($result->success) {            $order = $this->addToOrdersTablesPaypal(                $transaction->paypal['payerEmail'],                $transaction->paypal['payerFirstName'].' '.$transaction->paypal['payerLastName'],                null            );